Tub grinders are intended for use in grinding organic waste material (e.g., brush, wood, grass, leaves, paper, etc.). Conventional tub grinders include a rotary grinding member which is mounted on a frame for rotation about a horizontal axis. A rotating tub surrounds the grinding member. The tub rotates about a general vertical axis. Debris is deposited in the rotating tub and the rotary grinding member grinds the debris.
The rotary tub grinder may eject material from the tub resulting in projectiles being thrown from the tub during its use. Tub grinders are powerful machines. Commonly, a tub grinder may be powered by a 400 horsepower motor with the grinder rotating at about 2100 rpm. Occasionally, through misuse of the tub grinder or the like, metal or other undesired material may be admitted to the tub grinder.
Some conventional tub grinders include hoods to deflect material downwardly. Such hoods are positioned directly above the grinding member and have been used to limit the amount of material which may be deflected by the grinding member. However, even with such hoods, material may still be deflected out of the tub. Example hoods may be found in U.S. Pat. No. 4,585,180 (see item 34 in FIG. 4) and U.S. Pat. No. 6,412,715 (see item 50 in FIG. 6).
Notwithstanding the prior techniques for reducing deflection of material from a tub, additional improvements are desirable to reduce the amount of debris material being deflected for a tub grinder.